| 摘要 |
PURPOSE:To elevate the gain, by fixing a nozzle facing a flapper to a diaphragm, and adding additional back pressure in accordance with the extent of the displacement of the nozzle, in a nozzle flapper device used for a pneumatic meter, etc. CONSTITUTION:A nozzle 2 facing the tip of a flapper 1 is fixed in the center of a diaphragm 4 placed on a base 3. An inside space partitioned by a diaphragm 4 forms a nozzle back pressure chamber 5, pneumatic pressure Psup of constant pressure is supplied through an inlet passage 7 having an orifice 6 connected to the rear end side of the chamber 5, and a variation of nozzle back pressure Pn is outputted through an outlet passage 8 provided on the side of the chamber 5. According to such a constitution, when a displacement input is provided to the flapper 1, a space to the nozzle 2 is varied, and the nozzle 2 moves back and forth against the flapper 1, following a variation of the diaphragm 4 in accordance with a pressure variation in the chamber 5. Accordingly, when the flapper 1 rocks in the direction approaching the nozzle 2 and throttles the opening part of the nozzle, the back pressure Pn is increased and the gain is elevated. |
